To provide a fireproofing tool and a fireproofing structure capable of positioning a fire resistive material around wires and pipes within the body of the tool by a receptacle and blocking quickly the gap between a through-hole or sleeve and the body of the tool.

The fireproofing tool 11 is equipped with the body 12 of the tool formed cylindrically from a thermo-expansive rubber able to maintain its shape by itself and to be inserted into the through-hole Wa. The body 12 of the tool is equipped with a filling space opening at one end in the axial direction and enabling the body 12 to be filled with a thermo-expansive putty 21, and a receptacle part 16 to receive the putty 21 existing in the filling space at the other end in axial direction. The receptacle part 16 is so shaped as to be able to be penetrated by an electric wire pipe P. In the fireproofing structure, the body 12 is inserted into the through-hole Wa so that the aperture of the filling space is open at the open end of the through-hole Wa and the receptacle part 16 is positioned nearer the innermost than the open end of the through-hole Wa.